Various forms of power transmissions for use in driving land vehicles and the like have been heretofore provided and examples of various forms of power transmissions including some of the structural features of the instant invention are disclosed in U.S. Pat. Nos. 1,665,974, 2,799,175, 2,892,505, 2,930,246, 3,285,084 and 3,715,928.
However, while these previously known power transmission devices have in some instances been capable of instant reversing operation and others have been constructed in a manner whereby steerage of the associated vehicle may be accomplished by selectively driving opposite side wheels of the vehicle, most of these previously known power transmission devices have included complex drive arrangements and have not been operable to provide both instant reversing operation as well as vehicle steering ability by selectively driving opposite side wheels of the vehicle.